Subthalamic stimulation affects homophone meaning generation in Parkinson's disease

Abstract

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) in individuals withParkinson's disease (PD) has often been associated with reduced verbal fluency performance. This study aimed to directly assess semantic switching as a function of STN stimulation in PD participants with the Homophone Meaning Generation Test (HMGT). Seventeen participants with PD who had received STN DBS completed the HMGT in on and off stimulation conditions. Twenty-one non-neurologically impaired participants acted as controls. PD participants (in both on and off stimulation conditions) generated significantly fewer meanings than control participants and consistent with the previous reports of verbal fluency impairment, PD participants produced fewer definitions in the on stimulation condition. PD participants (in both on and off stimulation conditions) also had greater difficulty generating definitions for nonhomographic homophones compared with homographic homographs. The results of this study indicate that STN stimulation exacerbates impairment in semantic switching. (JINS, 2008, 14, 890-894.)

Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools

“…Such simulations can allow for 3D visualizations of the electric field influenced by the stimulation and match it to the patient's clinical outcome [5,80]. As DBS has become more commonly used, there have been increasing reports of postoperative neuropsychiatric complications, including depression, mania, aggression, and language disturbances [19,47,120]. Even though several hypothesis of the fundamental mechanisms exist underlying both the therapeutic effects and the adverse side effects of DBS, the mechanism remains largely unknown [27,38,76,84].…”